Gwen John, “Young Woman Holding a Black Cat” (c. 1920–25), oil on canvas, Tate Britain When London’s Tate Gallery opened in 1897, it contained 249 works by men and five by women.

The work of the painter Gwen John has always seemed at a careful remove from the revolutionary modernist spirit that we associate with Paris in the early 20th century. She arrived in the city in ...